black poop

Senior Guinea Pig

hi all. my guinea pig used to have brownish poop. today i noticed that it was more towards BLACK than brown and it was partially wet. at first i thought he might of peed on it but i checked and there were no pee stains. the water couldnt of gotten it either. anything i can do or is this normal?

thankss. XP

Edit:

i just noticed that his poop is kinda squishy. gilbert squished his poop! usually its hard...any suggestions on this?

Do you feed veggies daily? What veggies did you give him yesterday?
I find my piggies poo changes colour slightly depending on what they have to eat. Nothing to worry about unless it changes permanently, or you see any sign of blood, discharge, gunge etc